1. Field
This disclosure is related to video processing and, more particularly, to decoding video images.
2. Background
Due to implementation constraints, motion compensation hardware employed in video decoding is typically designed for a given video image resolution. For example, without limitation, the MPEG2 specification, ISO/IEC 13818-2 MPEG-2 Video Coding Standard, “Information technology—Generic coding of moving pictures and associated audio information: Video,” March, 1995, hereinafter referred to as “MPEG2,” may impose a video resolution of 720 pixels times 480 pixels at 30 frames per second. In a conventional design, the engine that performs the decoding will typically only generate images at the video resolution that the compressed video bit stream specifies. As a result of the amount of memory employed to hold decoded images, higher resolution compressed video bit streams, such as MPEG2 bit streams for digital television (DTV) content, for example, will not run on such a system. If sufficient memory is available to decode at the full specified resolution, and a user chooses to view the video on a smaller window on a computer platform, for example, downscaling is performed on the full size decoded image at display time and, therefore, full resolution decoding is still employed. A need, therefore, exists for a method or technique for a system to operate on or produce video resolutions other than the resolutions specified by the compressed video bit stream providing the video or image data.